Abrasion testing method

Abstract

An abrasion evaluation test method is applicable to a case where a rotating disk and a friction member to be brought into sliding contact with the disk contact and abrade each other even while a brake is not applied due to vibrations and mounting errors. The disk is an actual disk, and the friction member is a test piece which is smaller than the actual friction member. The test piece is pressed against a frictional surface of the disk at a predetermined position, thereof. The abrasion of the disk is measured with respect to a portion of the frictional surface that is out of contact with the test piece, while the abrasion of the friction member is obtained from the difference in thickness of the test piece before and after testing.

What is claimed is: 
     
       1. A testing method for evaluating the abrasion of rotating disks and friction members of brakes, wherein a friction member and a respective rotating disk of a brake contact each other and abrade while the brake is not applied due to vibrations and mounting errors, said testing method comprising the steps of: pressing a test piece friction member, which is smaller than an actual friction member, against a portion of a frictional surface of an actual disk at a predetermined position, maintaining a portion of the frictional surface out of contact with the test piece friction member and rotating the test piece friction member and the actual disk relative to each other;   measuring the degree of abrasion of the disk with respect to the portion of the frictional surface maintained out of contact with the test piece friction member; and   obtaining the degree of abrasion of the test piece friction member by determining the difference in the thickness of said test piece friction member before and after said step of pressing.   
     
     
       2. The testing method of claim 1, wherein the test piece friction member has a contact surface having a width a and a centerline of a length b that extends in a circumferential direction of the disk in said step of pressing;   the frictional surface of the disk has a width A and a circumference B at the centerline of the contact surface of the test piece friction member in said step of pressing;   during said step of pressing,   a=A/15-A/1.5, b=B/150-B/15 and b>a,     and the disk is rotated at a revolving speed of 300-3000 rpm;     said steps of pressing, measuring and obtaining are conducted for two different values of the surface pressure of the test piece friction member on the disk, the two different values being within a range of at least the surface pressure due to the weight of the test piece friction member by itself and at most 3 kg/cm 2 , the surface pressure multiplied by the area of the contact surface of the test piece friction member being at most 10 kg; and   the results from conducting said steps of pressing, measuring and obtaining for the two different values of the surface pressure are evaluated together.   
     
     
       3. A testing method for evaluating the abrasion of rotating disks of brakes having rotating disks and friction members for frictional contact with the rotating disks, said testing method comprising the steps of: pressing a test piece friction member, which is a test piece smaller than an actual one of the friction members, against a portion of a frictional surface of an actual one of the rotating disks at a predetermined position, maintaining a portion of the frictional surface out of contact with the test piece friction member and rotating the test piece friction member and the actual disk relative to each other; and   measuring the degree of abrasion of the disk with respect to the portion of the frictional surface maintained out of contact with the test piece friction member.   
     
     
       4. The testing method of claim 3, wherein: the test piece friction member has a contact surface having a width a and a centerline of a length b that extends in a circumferential direction of the disk in said step of pressing;   the frictional surface of the disk has a width A and a circumference B at the centerline of the contact surface of the test piece friction member in said step of pressing; and   during said step of pressing,   a=A/15-A/1.5, b=B/150-B/15 and b>a,     and the disk is rotated at a revolving speed of 300-3000 rpm.     
     
     
       5. The testing method of claim 4, wherein: said steps of pressing, measuring and obtaining are conducted for two different values of the surface pressure of the test piece friction member on the disk, the two different values being within a range of at least the surface pressure due to the weight of the test piece friction member by itself and at most 3 kg/cm 2 , the surface pressure multiplied by the area of the contact surface of the test piece friction member being at most 10 kg.